Disposable column cartridge

Abstract

A liquid chromatographic analytical column includes an end cap that is abutted with an end edge of a holder body when the analytical column is fully inserted into a bore in the holder body. An end cap mounted to a precolumn is compressed between the end cap of the analytical column and an end nut connected to a holder union. The holder union has a central passage that admits the precolumn therethrough and a stop that engages a ferrule placed around the precolumn to compress the ferrule against the analytical column end cap to form a seal.

What is claimed is: 
     
       1. A liquid chromatography cartridge column system comprising: an analytical column having an analytical column bore;   a precolumn having a precolumn bore;   a holder body having a bore therein;   a first end cap mounted upon a first end of the analytical column;   a second end cap mounted upon a first end of the precolumn, the second end cap having a portion formed to abut the end of the first end cap, so that the analytical column and the precolumn are axially aligned and abutting each other to form a fluid flow path between the analytical column bore and the precolumn bore;   a ferrule positioned around the second end cap;   means for compressing an end of the ferrule against the first end cap; and   means for urging the precolumn and the first end cap toward the end of the holder body.   
     
     
       2. The liquid chromatography cartridge column system of claim 1 wherein the means for compressing an end of the ferrule against the first end cap comprises: a threaded portion on the holder body proximate the holder body end; and   a holder union in threaded engagement with the threaded portion of of the holder body, the holder union including a passage for admitting the precolumn therethrough and a stop for engaging the ferrule, the ferrule being compressed between the end of the holder body and the stop as the holder union is advanced along the threaded portion of the holder body.   
     
     
       3. The liquid chromatography cartridge column system of claim 1 wherein the means for urging the precolumn and the first end cap toward the end of the holder body includes: a second threaded portion on the holder union; and   an end nut formed for threaded engagement with the second threaded portion of the holder union, the end nut including a cavity therein for receiving a second end of the precolumn, the precolumn being compressed between the first end cap and the end nut as the end nut is advanced into threaded engagement with the holder union.   
     
     
       4. The liquid chromatography cartridge column system of claim 3 wherein the means for compressing an end of the ferrule against the first end cap comprises: a threaded portion on the holder body proximate the holder body end; and   a holder union in threaded engagement with the threaded portion of of the holder body, the holder union including a passage for admitting the precolumn therethrough and a stop for engaging the ferrule, the ferrule being compressed between the end of the holder body and the stop as the holder union is advanced along the threaded portion of the holder body.   
     
     
       5. The liquid chromatography cartridge column system of claim 4, further comprising a cavity formed in the end of the first end cap for receiving the second end cap therein to align the analytical column tube and the precolumn tube and for providing a seat for an edge of the ferrule to form a seal. 
     
     
       6. A method for forming a high pressure seal around a fluid path formed by abutting a first end cap mounted to a chromatographic analytical column and a second end cap mounted to a precolumn, comprising the steps of: forming a bore in a holder body, the bore having a diameter less than the diameter of the first end cap;   inserting the analytical column in the bore such that the first end cap abuts and an end edge of the holder body;   abutting the first and second end caps;   placing a ferrule around the second end cap;   urging the ferrule toward an end of the first end cap; and   compressing the precolumn between an end nut and the end of the first end cap.   
     
     
       7. The method of claim 6, further including the steps of: forming a cavity in the end of the first end cap to provide a seat for the ferrule; and   compressing the ferrule against the seat.   
     
     
       8. A liquid chromatography cartridge column system comprising: an analytical column having an analytical column bore;   a precolumn having a precolumn bore;   the cross-sectional inner diameter of the analytical column bore and the precolumn bore being equal;   a first end cap mounted upon a first end of the analytical column;   a second end cap mounted upon a first end of the precolumn, the second end cap having a portion formed to abut the end of the first end cap, so that the analytical column and the precolumn are axially aligned and abutting each other to form a fluid flow path between the precolumn and the analytical column;   the analytical column having a first and second liquid filter positioned at each end, each of said filters being telescoped within said analytical column bore so that the outer diameter of said filters is at least equal to the diameter of said analytical column bore;   the precolumn having a third and fourth liquid filter positioned at each end, each of said filters being telescoped within said precolumn bore so that the outer diameter of said filters is at least equal to the diameter of said precolumn bore;   the analytical column and the precolumn being juxtaposed end to end so that the third filter of the precolumn is positioned in axial alignment with the second filter of the analytical column;   the liquid filters of the analytical column and the precolumn being secured by at least one end cap, each end cap positioned at the ends of each column;   each end cap having an outer diameter greater than the column to which it is affixed so that the column is telescoped within the inner diameter of the end cap and;   each end cap having an inner abutment shoulder for receiving the liquid filters and providing a seat for securing each filter in abutment against said shoulder on one side of each filter and against the tubular body of the column on the other side of each filter, so that the precolumn and the analytical column form a uniform flow path through the equal inner diameters of the columns.   
     
     
       9. The liquid chromatography cartridge system of claim 8, wherein a set of capillary tubing connectors surrounding a set of capillary tubes are positioned at each end of said liquid chromatography cartridge system, the cartridge system further including a third end cap of the precolumn, opposite said second end cap, mounted on the second end of the precolumn, and a fourth end cap mounted on the analytical column, opposite the first end cap, the third and fourth end caps having frustoconical seats for receiving and sealingly engaging capillary tubing connectors.